Air cylinder oiling



Sept. 9, 1941. J. w. PAGE 7 AIR CYLINDER OILI NG Filed Dec. 19, 1940 2Sheets-Sheet l Sept. 9, 1941. J. w. PAGE AIR CYLINDER OILING Filed Dec.19, 1940 2 Sheets-Sheet 2 MMN Patented Sept. 9, 1941 AIR CYLINDER OILINGJohn W. Page, Chicago, 111., assignor to Page Engineering Company, acorporation of Illinois Application December 19, 1940, Serial No. eraser4 Claims.

This invention relates to improvements in air cylinders and moreespecially to an air cylinder adapted for use in connection withmechanism for supporting the intermediate portion of a relatively longheavy boom as is commonly used in derrick construction.

It has been customary heretofore to provide a support for a derrick boomat the center, but where such support was a fixed length difficulty wasencountered when the end of the boom changed position. By the use of myinvention an extensible and contractible supporting means is providedfor the center part of the boom, such means exerting a substantiallyconstant pull in all of its positions.

Another feature of my invention is the provision of means for insuringadequate lubrication of the piston in an air cylinder of the characterdescribed.

Other features and advantages of my invention will appear more fully asI proceed with my specification.

In that form of device embodying the features of my inventionillustrated in the accompanying drawings, Fig. 1 is a view in sideelevation of a derrick showing the complete boom supporting mechanism;Fig. 2 is a top plan view of the same; Fig. 3 is an enlarged top view ofthe pneumatic cylinder; Fig. l is a vertical sectional view of the same;Fig. is a view taken as indicated by the line 5 of Fig, 4; and Fig. 6 isan enlarged diagrammatic view of the air inlet and outlet for thecylinder.

As shown in the drawings, Ill may indicate in general a suitablestructure mounted on the base H and carrying the boom l2 pivotallyattached at l3. The boom is supported at its outer end by means of thefixed line H attached to the upper end of the floating mast or A frameI5, the lower end of which is pivoted at l6. The upper end of the Aframe I5 is adjustably held by the reeved line H, the end Ila of whichis controlled by suitable winding machinery on the structure It).

Because of the length of the boom and its weight, it is desirable toprovide means for supporting it between the ends. The fixed line M willstretch somewhat under load and since the pivots l3 and I6 are notcoincident there will be some variation in the distance between thecenter of the boom and the top of the A frame 15 in ordinary usage.Accordingly, if the supporting means for the central portionof the boomis of fixed length there will be some undesirable bending of the boom.If the supporting means is.

provided with a spring or equivalent member then the tension or pull ofthe supporting means will not be constant. The principal feature of myinvention is to provide such supporting means for the boom intermediateits ends, that is extensible and contractible, and a means that willexert a substantially constant pull in all its positions. This I shallnow describe more in detail.

l9 indicates a bridle cable with its ends attached to the side memberl2a and I2?) of the boom intermediate the ends. As here shown, theattachment is somewhat higher than the middle point. The bridle cable l9passes over the pulley 2i] fastened to the piston rod 2| which in turncarries the piston 22 in the cylinder 23 attached to the upper end ofthe A frame l5. Fluid pressure is supplied to the cylinder 23 in thespace 24 through the pipe 25 by any suitable means (not shown) tomaintain a substantially constant pull on the piston rod 2| and thusgive a substantially constant support to the boom I2.

It is to be understood that the pressure in the space 24 is maintainedsubstantially constant regardless of the position of the piston 22. Thiscan be accomplished in any suitable manner. For example, the space 24can be connected to a suitable air pressure tank provided with a pumpand safety valve so that an adequate supply of air at a constantpressure is always available. It is also possible to supply air at aconstant pressure to the space 24 through a pressure-reducing valve ofwell known construction.

The principal feature of this invention is the provision of means forinsuring continuous and positive lubrication to the interior of thecylinder 23 so that the wear on the piston will be reduced to a minimum.In the ordinary operation of this apparatus the center part of the boomI2 will vibrate upwardly and downwardly a great deal. This will causeback and forth movement of the piston 22 in the cylinder. In fact, itwill be seen that the piston 22 will be cushioned upon compressed air inthe space 24. The piston will vibrate to a great extent on this cushion.Therefore, there will be considerable wear in the cylinder unlessadequate lubrication is provided.

In the ordinary use of the device the piston 23 will be on a slightslant as shown in Figs. 1 and 4. I have provided a pool of oil in thelow end of the cylinder as indicated by 26 in Fig. 4. 2'. indicates anair inlet entering the cylinder below the level of the oil pool. This isconnected to a port 21a in the cylinder head 23a which in turn isconnected to the inlet pipe 21b, attached to the cylinder head near theupper edge. At one side of the pipe 21b is the outlet pipe 281)connected to the outlet 28 in the cylinder above the oil level. The pipe212) is provided with a check valve 210 permitting air to enter thecylinder only. The pipe 28b is provided with a check valve 280permitting air to escape from the cylinder only. The pipes 21b, 28b and25 are connected in a T.

It will be seen, therefore, that vibrating or While I have shown anddescribed certain embodiments of my invention, it isto. be understoodthat it is capable of many modifica-.

tions. Changes, therefore, in the construction and arrangement may bemade without departing from the spirit and scope of the invention asdisclosed in the appended claims, in which it is my intention to claimall novelty inherent in my invention as broadly as. permissible, in viewof the prior art.

What I claim as new and desire to secure by Letters Patent is:

1. In an air cylinder having a vibrating piston therein, a pool of oilin the cylinder, an air inlet below the oil level, an air outlet, and aconnection between the inlet and the outlet.

2. In an air cylinder having a vibrating piston therein, a pool of oilin the cylinder, an air inlet below the oil level, an air outlet abovethe oil level, and a connection between the inlet and the outlet.

3. A device of the character described, including: a cylinder; a pistontherein; a pool of .oil in the cylinder; an air inlet entering thecylinder below the level of the oil pool; and an air outlet from thecylinder above the level of the oil pool, said inlet and outlet beingconnected outside of the cylinder. I

4. A device as claimed in claim 3, in which the connection between theinlet and outlet is connected to a source of compressed air.

I JOHN W. PAGE.

